Rotary boring tools operating with jets of fluid



March 21, 1957 s. GSTALDER ETAL' 3,

ROTARY BORING TOOLS OPERATING WITH JETS OF FLUID 4 Sheets-Sheet 1 Filed May 25, 1964 55/?65 GSTALDEE BY Jim/v PAY/VAL March 21, 1967 GSTALDER ETAL 3,310,126

ROTARY BORING TOOLS OPERATING WITH JETS OF FLUID Filed May 25, 1964 v 4 Sheets-Sheet 2 N VE/VTGRS 5EPGE G5 THL DER JZ-HA/ A34 WW? 1.

,4 TTORNEKS March 1967 s. GSTALDER ETAL 3,310,126

ROTARY BORING TOOLS OPERATING WITH JETS OF FLUID Filed May 25, 1964 4 Sheets-Sheet 5 SERGE Gar/m 05/2 JZ-"A/v PAY/m1.

y aW I/M HTTOPNE Y5 March 21, 1967 s. GSTALDER ETAL 3,

ROTARY BORING TOOLS OPERATING WITH JETS 0F FLUID Filed May 25, 1964 4 Sheets-$heet 4 IN W? N TORS S15E 5 GST/ILDER Jbyv P4 YN/IL United States Patent 3,310,126 ROTARY BORING TQQLS OPERATING WITH JETS 0F FLUID Serge Gstalder and Jean Raynal, Pau, Basses-Pyrenees,

France, assignors to Societe Anonyme: Societe Nationale des Petroles dAquitaine, Paris, France Filed May 25, 1964, Eer. No. 370,005 Claims priority, application France, May 28, 1963, 936,172 9 Claims. (Cl. 175329) The present invention relates to improvements in rotary boring tools operating with jets of fluid, of the type comprising a central inlet channel for a pressurised boring fluid, a head comprising adjacent boring areas or sections provided with delivery apertures for the distribution of the boring fluid perpendicularly to the surface of said sections, and boring members secured to at least one of these sections. These boring members may be diamonds, tungsten carbide, or cutting blades.

It is known that in such tools for use in shaft boring through rock, the jets of liquid distributed by the delivery apertures effect a clearing away of cake or deposit of solid particles contained in the mud and of the splinters of rock adhering to the surface of the base of the shaft, as well as assist in the destruction of the rock by a jet effect in the course of their impact against the bottom of the shaft. The fluid distributed in this manner also ensures the cooling of the boring members and their cleaning.

The two parallel side walls of the very narrow delivery apertures, immediately adjacent the outer surface of the boring areas, are disposed lengthwise along lines extending from adjacent the center of the working face of the head outwardly to the outer periphery of the boring area of the boring head and follow the curve of the surface of the tool and which lines will be hereinafter designated by the term meridian. The internal walls of a delivery aperture adjacent to the surface of the tool are tangential, along the whole length of a meridian, to a cylinder having generatrices parallel to the axis of the tool and which touches said meridian.

In order to make optimum use of the action of the rigid-like fluid jets, the number of delivery apertures should be as large as possible, but taking into account the resulting increase in the section of passage of the boring fluid, an increase of this type beyond a certain limit, would result in the reduction of the speed of outlet of said fluid with consequent reduction in the jet effect. Assuming that the delivery apertures are all of the same width but of varying length, it is therefore necessary to remain within a certain limit regarding the total length of the various delivery apertures in order to maintain a relatively high outle speed of the fluid which may reach and even exceed 150 m./s.

Furthermore a delivery aperture distributing a fluid jet is in practice provided in a boring fluid discharge groove which forms a narrow area separating two abrasive areas. The profile surface of this narrow area in the direction of a meridian is off-set in height with respect to the abrasive area so that there is no contact between said area and the base of the shaft. This off-setting may however be slight in order to maintain maximum effectiveness of the jet.

It is also known that the speed of advance of a boring tool of this type is reduced in practice by the fact that the tangential speed of the boring members located in its central area is less than the speed of these members located at a greater distance from the center.

The improvements forming an object of the present invention in boring tools of the type hereinbefore defined consist in means serving to ensure a maximum ejec- "ice tion speed of the fluid, to improve the supply of Water to the boring areas and to the bottom of the shaft being bored, as well as to compensate for the reduced speed of advance of the tool due to the low tangential speed of its central boring area.

The invention consists in a boring tool operating with jets of fluid of the type comprising a central channel for the inlet of pressurized boring fluid, a head comprising a plurality of adjacent areas provided with delivery apertures for the distribution of the boring fluid perpendicularly to the surface of said areas, and boring members secured to at least one of said areas said boring members consisting of diamonds, tungsten carbide, or cutting blades, wherein narrow recessed areas separate the boring areas for discharging boring fluid. The delivery apertures for the jets of fluid towards the surface of the head of the tool are preferably of uniform width but are of a length less than the total length of a meridian and said apertures are distributed and arranged along the meridians in such a manner that the number of these apertures counted on any meridian is desirably at least one, and wherein the apertures of the various meridians describe circular patterns in the course of rotation of the tool, the assembly of said'circular patterns covering all the boring surface of the tool, and the sum of the length of the various apertures being equal to the length of at least one meridian, said sum of the length being selected as a function of the thickness of the jet of fluid and of the desired speed of ejection.

The fluid jet outlet apertures may be distributed on the meridians in such a manner that the number of the apertures, counted peripherally, is greater towards the center of the drilling area than towards its periphery.

Each narrow area separating two drilling areas may have, in the direction of a meridian, a profiled incurved surface providing a discharge groove, the one end of the side of the groove of which is shifted in an upward direction with respect to the ends of the boring members by at the most one height of such a member, while the other end of this profiled surface is shifted in an upward direction by a greater height.

In order that the invention may be more clearly understood, reference will now be made to the accompanying drawings which show some embodiments thereof by way of example, and in which:

FIGURE 1 is an end view of a boring tool according to the invention.

FIGURE 2 is a view showing diagrammatically one mode of distribution of the fluid jet outlet apertures on the various meridian-s of a tool according to the invention,

FIGURES 3a and 3b are sectional views along the line III-III of FIGURE 1 showing diagrammatically the profiled surfaces respectively of a narrow area in the direction of a meridian of a known drilling tool having fluid jets and of a tool embodying the improvements according to the invention,

FIGURE 4 is a sectional view of a tool along the line IV1V of FIGURE 1, said section only showing the elements of the tool contained in the plane IVIV.

FIGURE 5 is a sectional view of a tool along the line VV of FIGURE 1, said section only showing the different elements of the tool contained in the plane IV-IV,

FIGURE 6 is a sectional View of a tool along the line YVIVI of FIGURES 1 and 5, said section also only showing the elements of the tool contained in the plane VI-VI, with the exception of the upper part of a mudchannel which is shown in dotted lines, and

FIGURES 7 to 9 are sections along the lines VII-VII, VIIIVIII, IXIX of FIGURE 4, showing the variations in the section of a mud-channel for the distribution of pressurized boring fluid beginning with the central channel of the tool and opening on to a boring area.

' First referring to FIGURE 1, the boring tool there shown in end view has five adjacent zones bearing reference numerals 1, 2, 3, 4 and 5. Each of these identical zones comprises a boring area such as at lla bearing boring members 6, for example diamonds, and a narrow area providing a boring fluid discharge groove, Such as as 1b separating the boring areas. Narrow, short, generally rectangular shape, fluid delivery apertures such as as are provided in the head of the tool and constitute elongated outlets arranged length-wise along meridians for boring fluid which is conveyed under strong pressure by a central conduit of the tool, the jets of fluid being discharged from the apertures perpendicularly to the surface of the tool.

In FIGURE 1, the zones 1 and 2 are shown with the delivery apertures 10 and provided in the trailing or rearward part of the narrow areas or discharge grooves 1b and 2b respectively, referring to the direction of rotation of the tool shown by the arrow F.

In a modification these apertures are provided towards the leading or forward part of the boring areas as shown at 30, 4c and 5c in the zones 3, 4 and 5, also in FIGURE 1. These apertures may be located in any other part of these areas and in particular towards the center of said areas. A part of the mud or boring fluid discharged from the apertures 30, 4c and 50 could then only reach the discharge grooves such as Ib and 2b by passing under or in other words, across the face of an element such as B and B provided with diamonds or abrasive elements. At the limit, the discharge grooves such as 11) and 2b may have a very slight breadth with respect to the breadth of the abrasive surfaces.

In many known tools utilising jets of fluid and which have a reduced number of boring areas, generally two or three, the fluid delivery apertures provided in the narrow areas separating two boring areas extend throughout the length of the meridians.

In a tool according to the invention each of the delivery apertures provided either in a discharge groove or in a drilling are-a is elongated and extends along a meridian, the length of each aperture being only a fraction of the length of a meridian.

On the zone 5, there has also been shown channels w generally described as waterways, provided in the boring area 5a and here connected with the fluid delivery apertures 5c. Channels of this type may thus be provided in order to improve the supply of water or boring fluid to the boring area.

In FIGURE 2 has been diagrammatically shown an arrangement of these various apertures, by way of example. The various meridians shown have been given the reference numerals 1 ,2, 3, 4 and 5 corresponding to the same reference numerals which indicate, in FIGURE 1, the various zones.

The apertures provided on the various meridians are in this embodiment distributed on each meridian in the following manner. First of all the number of these apertures counted on any meridian is at least one; in this embodiment this number is three, 30, 4c and 50, adjacent to the center of the tool, i.e., at the upper end CC of FIG- URE 2, three, 10, 2c and 46 at the center and one, 10, on the periphery of the tool, i.e. at the lOWer extremity PP. The distribution is arranged in this manner in order to compensate for the ditference in tangential speed'of the boring members according to their distance from the center of the tool, by a greater jet effect towards tthe upper end CC which represents the central part of the tool, than at its lower end PP which represents its periphery.

It will be seen that in FIGURES 1 and 2, there have been shown for zones 1, 4 and 5, apertures of a length equal to unit length, and for zones 2 and 3 apertures of a length equal either to the preceding ones, or of double their length, this being only by way of example.

The various apertures have been arranged on the tool in such a manner that when they describe circular patterns as a result of the rotation of the tool, the assembly of circles described covers the whole boring surface, or to put it another way, starting from the center of the tool, i.e. starting from the upper end CC of FIGURE 2, showing the meridians, the end of an aperture of a meridians corresponds to the beginning of an aperture of another meridian with or without overlapping.

Finally the sum of the length of the various apertures arranged on the various meridians is equal to at least the length of one meridian. In FIGURE 2, the various apertures have been shown of a uniform length equal to /s of the length of a meridian, a double aperture such as 20 and 3c being considered as two contiguous apertures. Eleven unit length apertures have been provided, which represent a little more than the length of two meridians.

The distribution of the various apertures on the different meridians and the number of these latter may, of course, be different from that shown in FIGURE 2.

It is for example possible to effect distribution of five apertures of a unit length equal to /5 of the length of a meridian, by locating one aperture on each of the five meridians, each aperture being off-set with respect to each other aperture in order to cover the whole boring surface. It is again possible to distribute fourteen apertures of a unit length equal to of the length of a meridian, by locating said apertures two by two on each of seven meridians.

With regard to the ejection speeds, the total length of the assembly of apertures provided is usually approximately the length of two meridians, in spite of the fact that the number of assemblies of adjacent areas is greater than that of a known tool with jets of fluid. The nozzle eifect of the jets issuing from said apertures consequently maintains maximum effectiveness.

It is thus easy to understand that the increase in the number of meridians provided with apertures substantially improves the washing and the cooling of the boring zone areas of the tool.

This action may be further improved by modifying the form, in a known tool of this type of the narrow area or discharge grooves at the level of a delivery aperture.

In FIGURE 3a is shown, diagrammatically, a known profiled surface, the wall A, B vertically defining the side of a fluid distributing channel opposite the area carrying the boring members 6 and given the same reference numeral 2a as in FIGURE 1, and BC, defining the narrow area or discharge groove 2b between the point B and the boring area In, having sections which intersect at The wall BC is recessed with respect to the end of the boring members 6 by a height greater than that of said members.

An arrangement of this type means in practice insuflicient washing with water of the parts provided with diamonds and a uniform high static pressure along the line BC which does not allow for a rapid removal of the splinters of rock produced by the tool.

The section IIIIII shown in FIGURE 3b in the same diagrammatic manner as in FIGURE 3a shows a profiled surface of the fluid discharge grooves or narrow area 2b according to the invention. The ends B and B" of the walls A, B, and A, B" defining the delivery apertures 20 and 1c respectively are extended in a downward direction to a distance, from the level of the ends of the boring members, at the most equal to the height thereof, while the walls B, C and B, C defining the narrow areas 2b and 1b have an incurved form such that the points C and C are shifted upwards by a greater amount.

The result of this arrangement is that the pressure of the boring fluid is increased at the delivery apertures, for example towards B, while the pressure at C is less, this bringing about a flow of one part of the boring fluid in the direction of the arrow 7 which is the opposite direction to the direction F of the rotary movement of the tool, and consequently of substantially improving the Washing of the boring areas. At the same time the static pressure in the part with minimum passage sectionat B or B is reduced with respect to that along the line BC of FIGURE 3a.

By combining the arrangements of the apertures on the various meridians With that of the profiled incurved surface of the narrow areas as has been described, and possibly also with the irrigation channels connected to the said apertures, a substantially increased yield is obtained from a boring tool having fluid jets.

In order to make clearer the different sections on FIG- URES l, and 4 to 6 the reference numerals a a a a a a a a e e e e e and e have been used. As can be seen in FIGURES 7 to 9, the sections S1, S2, S3 of a mud channel decrease towards the point at which this channel opens on to the drilling surf-ace of the tool, in such a manner that the lower section of the channel is always smaller than a higher section of the said channel (S1 is greater than S2 which is greater than S3). The length l of the lower section S3 of a channel is selected in such a manner that the sum of the length of the lower sections of the apertures arranged on the tool is equal to the length of at least one meridian and the width or thickness e of a lower section S3 is selected as a function of the total length of the apertures and of the desired speed of ejection of a jet of fluid.

We claim:

1. A rotary boring tool operating with jets of fluid, comprising: a boring head having adjacent areas in the working face thereof provided with a plurality of elongated fluid delivery apertures in the outer surface thereof for the distribution of boring fluid under pressure perpendicular to said surface, said boring head having a central channel connected with said delivery apertures for the passage of pressurized boring fluid; boring members secured to said areas forming boring areas; boring fluid discharge grooves separating said boring areas; said elongated delivery apertures for jets of boring fluid being arranged lengthwise along a plurality of meridians extending from adjacent the center of said working face outwardly to the outer periphery of the boring area of the 'boring head, the fluid delivery apertures of the various meridians describing circular patterns during rotation of said tool, the assembly of said circular patterns covering all the boring area of said tool, and the sum of the length of all of the apertures being equal to the length of at least one meridian.

2. A tool as claimed in claim 1, wherein the number of said apertures counted peripherally is greater towards the center of the boring area than towards its periphery.

3. A tool as claimed in claim 1, wherein at least one of said apertures is arranged on a meridian in a discharge groove and along the trailing edge thereof with respect to the direction of rotation of said tool.

4. A tool as claimed in claim 1, wherein at least one of said apertures is arranged on a meridian in at least one of said boring areas.

5. A tool as claimed in claim 4, wherein at least one waterway is provided in at least one of said boring areas having an aperture arranged therein, said waterway being connected to the aperture of the corresponding boring area and extending from the said aperture in a direction generally downstream thereof with respect to the direction of rotation of said tool.

6. A tool as claimed in claim 1, wherein each one of said discharge grooves has, in the direction of a meridian, a profiled incurved surface, the upstream side of said grooves being recessed to a greater height than the downstream side thereof with respect to the direction of rotation of the tool.

7. A tool as claimed in claim 1, wherein a plurality of said apertures are arranged on meridians in a plurality of said boring areas adjacent the upstream side of said boring areas with respect to the direction of rotation of the tool being spaced a short distance from said apertures in said boring areas whereby at least a part of the boring fluid leaving said apertures in said boring areas passes under at least a part of the corresponding boring area.

8. A tool as claimed in claim 1, wherein said discharge grooves have a width less than the Width of said boring areas.

9. A tool as claimed in claim 1 wherein said delivery apertures are substantially rectangular as viewed in transverse cross-section and the number of said delivery apertures counted on any one of said meridians is at least one.

References Cited by the Examiner UNITED STATES PATENTS Re. 25,319 1/1963 Short -329 2,371,489 3/ 1945 Williams 175-329 2,371,490 3/1945 Williams 175-329 2,381,415 8/ 1945 Williams 175-329 3,112,803 12/ 1963 Rowley 175-329 CHARLES E. OCONNELL, Primary Examiner.

N. C. BYERS, Assistant Exxaminer. 

1. A ROTARY BORING TOOL OPERATING WITH JETS OF FLUID, COMPRISING: A BORING HEAD HAVING ADJACENT AREAS IN THE WORKING FACE THEREOF PROVIDED WITH A PLURALITY OF ELONGATED FLUID DELIVERY APERTURES IN THE OUTER SURFACE THEREOF FOR THE DISTRIBUTION OF BORING FLUID UNDER PRESSURE PERPENDICULAR TO SAID SURFACE, SAID BORING HEAD HAVING A CENTRAL CHANNEL CONNECTED WITH SAID DELIVERY APERTURES FOR THE PASSAGE OF PRESSURIZED BORING FLUID; BORING MEMBERS SECURED TO SAID AREAS FORMING BORING AREAS; BORING FLUID DISCHARGE GROOVES SEPARATING SAID BORING AREAS; SAID ELONGATED DELIVERY APERTURES FOR JETS OF BORING FLUID BEING ARRANGED LENGTHWISE ALONG A PLURALITY OF MERIDIANS EXTENDING FROM ADJACENT THE CENTER OF SAID WORKING FACE OUTWARDLY TO THE OUTER PERIPHERY OF THE BORING AREA OF THE BORING HEAD, THE FLUID DELIVERY APERTURES OF THE VARIOUS MERIDIANS DESCRIBING CIRCULAR PATTERNS DURING ROTATION OF SAID TOOL, THE ASSEMBLY OF SAID CIRCULAR PATTERNS COVERING ALL THE BORING AREA OF SAID TOOL, AND THE SUM OF THE LENGTH OF ALL OF THE APERTURES BEING EQUAL TO THE LENGTH OF AT LEAST ONE MERIDIAN. 